Recently, various types of optical disks are being proposed as disk-type information recording media which are for use on recording/reproducing apparatuses in a detachable manner. These recordable optical disks are being proposed as mass storage media of several gigabytes, which are highly expected as media for recording AV (Audio Visual) signals such as video signals. The sources (or the supply sources) of digital AV signals to be recorded on recordable optical disks include CS digital satellite broadcast and BS digital broadcast signals and, in the future, digital ground-based television broadcast signals.
Generally, the digital video signals supplied from these sources are image-compressed by MPEG2 (Moving Picture Experts Group 2). Each recording apparatus has its unique recording rate. When the digital video signals of digital broadcasting are recorded by use of conventional consumer video storage media, the digital video signals are decoded to perform band limitation before being recorded in the case of analog recording. Alternatively, in the case of digital recording such as MPEG1 Video, MPEG2 Video, and DV (Digital Video), the digital video signals are decoded once and encoded again with the device-unique recording rate and encoding algorithm before being recorded.
However, the above-mentioned recording schemes involve the degradation in picture quality because the supplied bit streams are decoded once and then band-limited and encoded again before being recorded. When picture-compressed digital signals are recorded, if the transfer rate of the inputted digital signals does not exceed the recording rate of the recording/reproducing apparatus used, a recording method in which the supplied bit streams are directed recorded without decoding and re-encoding least degrades the picture quality. However, if the transfer rate of the picture-compressed digital signals exceeds the recording rate of a disk of recording medium, it is required for the recording/reproducing apparatus to re-encode the digital signals for recording so that the transfer rate after the decoding on the recording/reproducing apparatus becomes less than the upper limit of the disk recording rate.
If a digital signal is transmitted by a variable rate scheme in which the bit rate of an inputted digital signal goes up and down with time, a disk recording apparatus in which data are stored once in its buffer for burst recording can use the disk capacity less wasteful as an information recording medium than a tape-recording apparatus in which the recording rate is fixed because the rotary head has a fixed rotational speed.
Thus, in the future in which the digital broadcasting becomes the mainstream broadcasting, such recording/reproducing apparatuses using disks as recording media will be required as recording broadcast signals as they are digital without decoding and re-encoding like data streamers.
As described above, as the storage capacity of recording media increases, each recording medium will be able to recording lots of data (for example, video data and audio data associated with programs) to record many programs to a single disk. In such a situation, each user is required to perform operations such as copying of desired data selected from among many programs recorded to a disk to another disk.
However, if a copy operation is performed, it becomes difficult to properly managing the contents of the recorded data and the reproduction information.